Canvas

Available since LÖVE 0.8.0
It has been renamed from Framebuffer.

A Canvas is used for off-screen rendering. Think of it as an invisible screen that you can draw to, but that will not be visible until you draw it to the actual visible screen. It is also known as "render to texture".

By drawing things that do not change position often (such as background items) to the Canvas, and then drawing the entire Canvas instead of each item, you can reduce the number of draw operations performed each frame.

In versions prior to 0.10.0, not all graphics cards that LÖVE supported could use Canvases. love.graphics.isSupported("canvas") could be used to check for support at runtime.


When drawing content to a Canvas using regular alpha blending, the alpha values of the content get multiplied with its RGB values.

Therefore the Canvas' pixel colors will have premultiplied alpha once it has been drawn to, so when drawing the Canvas to the screen or to another Canvas you must use premultiplied alpha blending – love.graphics.setBlendMode("alpha", "premultiplied").

Constructors

love.graphics.newCanvas Creates a new Canvas. 0.8.0

Functions

Canvas:clear Clears the contents of a Canvas to a specific color. 0.8.0 0.10.0
Canvas:generateMipmaps Generates mipmaps for the Canvas, based on the contents of the highest-resolution mipmap level. 11.0
Canvas:getFSAA Gets the number of FSAA samples used when drawing to the Canvas. 0.9.1 0.10.0
Canvas:getFormat Gets the texture format of the Canvas. 0.9.1 11.0
Canvas:getImageData Generates ImageData from the contents of the Canvas. 0.8.0 0.10.0
Canvas:getMSAA Gets the number of MSAA samples used when drawing to the Canvas. 0.9.2
Canvas:getMipmapMode Gets the MipmapMode this Canvas was created with. 11.0
Canvas:getPixel Gets the pixel at the specified position in a Canvas. 0.9.0 0.10.0
Canvas:newImageData Generates ImageData from the contents of the Canvas. 0.10.0
Canvas:renderTo Render to a Canvas using a function. 0.8.0
Object:release Immediately destroys the object's Lua reference. 11.0
Object:type Gets the type of the object as a string.
Object:typeOf Checks whether an object is of a certain type.
Texture:getDPIScale Gets the DPI scale factor of the Texture. 11.0
Texture:getDepth Gets the depth of a Volume Texture. 11.0
Texture:getDepthSampleMode Gets the comparison mode used when sampling from a depth texture in a shader. 11.0
Texture:getDimensions Gets the width and height of the Texture. 0.9.0
Texture:getFilter Gets the filter mode of the Texture.
Texture:getFormat Gets the pixel format of the Texture. 11.0
Texture:getHeight Gets the height of the Texture.
Texture:getLayerCount Gets the number of layers / slices in an Array Texture. 11.0
Texture:getMipmapCount Gets the number of mipmaps contained in the Texture. 11.0
Texture:getMipmapFilter Gets the mipmap filter mode for a Texture. 0.9.0
Texture:getPixelDimensions Gets the width and height in pixels of the Texture. 11.0
Texture:getPixelHeight Gets the height in pixels of the Texture. 11.0
Texture:getPixelWidth Gets the width in pixels of the Texture. 11.0
Texture:getTextureType Gets the type of the Texture. 11.0
Texture:getWidth Gets the width of the Texture.
Texture:getWrap Gets the wrapping properties of a Texture.
Texture:isReadable Gets whether the Texture can be drawn sent to a Shader. 11.0
Texture:setDepthSampleMode Sets the comparison mode used when sampling from a depth texture in a shader. 11.0
Texture:setFilter Sets the filter mode of the Texture.
Texture:setMipmapFilter Sets the mipmap filter mode for a Texture. 0.9.0
Texture:setWrap Sets the wrapping properties of a Texture.

Enums

MipmapMode Controls whether a Canvas has mipmaps, and its behaviour when it does. 11.0

Supertypes

Examples

Drawing something to the Canvas and then draw the Canvas to the screen.

function love.load()
    canvas = love.graphics.newCanvas(800, 600)
 
    -- Rectangle is drawn to the canvas with the regular alpha blend mode.
    love.graphics.setCanvas(canvas)
        love.graphics.clear()
        love.graphics.setBlendMode("alpha")
        love.graphics.setColor(1, 0, 0, 0.5)
        love.graphics.rectangle('fill', 0, 0, 100, 100)
    love.graphics.setCanvas()
end
 
function love.draw()
    -- very important!: reset color before drawing to canvas to have colors properly displayed
    -- see discussion here: https://love2d.org/forums/viewtopic.php?f=4&p=211418#p211418
    love.graphics.setColor(1, 1, 1, 1)
 
    -- The rectangle from the Canvas was already alpha blended.
    -- Use the premultiplied alpha blend mode when drawing the Canvas itself to prevent improper blending.
    love.graphics.setBlendMode("alpha", "premultiplied")
    love.graphics.draw(canvas)
    -- Observe the difference if the Canvas is drawn with the regular alpha blend mode instead.
    love.graphics.setBlendMode("alpha")
    love.graphics.draw(canvas, 100, 0)
 
    -- Rectangle is drawn directly to the screen with the regular alpha blend mode.
    love.graphics.setBlendMode("alpha")
    love.graphics.setColor(1, 0, 0, 0.5)
    love.graphics.rectangle('fill', 200, 0, 100, 100)
end

See Also


© 2006–2020 LÖVE Development Team
Licensed under the GNU Free Documentation License, Version 1.3.
https://love2d.org/wiki/Canvas